javascript图片切换

JavaScript 图片滑动切换效果

作者：cloudgamer　时间： 2009-09-25　文档类型：原创　来自：蓝色理想

第 1 页 JavaScript 图片滑动切换效果 [1]
第 2 页 JavaScript 图片滑动切换效果 [2]

序一（08/07/06）
看到 alibaba 的一个图片切换效果，感觉不错，想拿来用用。但代码一大堆的，看着昏，还是自己来吧。
由于有了做图片滑动展示效果的经验，做这个就容易得多了。
序二（09/03/19）
自写了 Tween缓动之后就很想重新写过这个效果，近来有点时间，终于可以动手了。
除了改成Tween缓动，也改进了程序算法，不过原理还是一样的。

效果预览：

运行代码框
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> <title>JavaScript 图片滑动切换效果</title> <script type="text/javascript"> var $ = function (id) { return "string" == typeof id ? document.getElementById(id) : id; }; var Extend = function(destination, source) { for (var property in source) { destination[property] = source[property]; } return destination; } var CurrentStyle = function(element){ return element.currentStyle || document.defaultView.getComputedStyle(element, null); } var Bind = function(object, fun) { var args = Array.prototype.slice.call(arguments).slice(2); return function() { return fun.apply(object, args.concat(Array.prototype.slice.call(arguments))); } } var Tween = { Quart: { easeOut: function(t,b,c,d){ return -c * ((t=t/d-1)*t*t*t - 1) + b; } }, Back: { easeOut: function(t,b,c,d,s){ if (s == undefined) s = 1.70158; return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b; } }, Bounce: { easeOut: function(t,b,c,d){ if ((t/=d) < (1/2.75)) { return c*(7.5625*t*t) + b; } else if (t < (2/2.75)) { return c*(7.5625*(t-=(1.5/2.75))*t + .75) + b; } else if (t < (2.5/2.75)) { return c*(7.5625*(t-=(2.25/2.75))*t + .9375) + b; } else { return c*(7.5625*(t-=(2.625/2.75))*t + .984375) + b; } } } } //容器对象,滑动对象,切换数量 var SlideTrans = function(container, slider, count, options) { this._slider = $(slider); this._container = $(container);//容器对象 this._timer = null;//定时器 this._count = Math.abs(count);//切换数量 this._target = 0;//目标值 this._t = this._b = this._c = 0;//tween参数 this.Index = 0;//当前索引 this.SetOptions(options); this.Auto = !!this.options.Auto; this.Duration = Math.abs(this.options.Duration); this.Time = Math.abs(this.options.Time); this.Pause = Math.abs(this.options.Pause); this.Tween = this.options.Tween; this.onStart = this.options.onStart; this.onFinish = this.options.onFinish; var bVertical = !!this.options.Vertical; this._css = bVertical ? "top" : "left";//方向 //样式设置 var p = CurrentStyle(this._container).position; p == "relative" || p == "absolute" || (this._container.style.position = "relative"); this._container.style.overflow = "hidden"; this._slider.style.position = "absolute"; this.Change = this.options.Change ? this.options.Change : this._slider[bVertical ? "offsetHeight" : "offsetWidth"] / this._count; }; SlideTrans.prototype = { //设置默认属性 SetOptions: function(options) { this.options = {//默认值 Vertical: true,//是否垂直方向（方向不能改） Auto: true,//是否自动 Change: 0,//改变量 Duration: 50,//滑动持续时间 Time: 10,//滑动延时 Pause: 2000,//停顿时间(Auto为true时有效) onStart: function(){},//开始转换时执行 onFinish: function(){},//完成转换时执行 Tween: Tween.Quart.easeOut//tween算子 }; Extend(this.options, options || {}); }, //开始切换 Run: function(index) { //修正index index == undefined && (index = this.Index); index < 0 && (index = this._count - 1) || index >= this._count && (index = 0); //设置参数 this._target = -Math.abs(this.Change) * (this.Index = index); this._t = 0; this._b = parseInt(CurrentStyle(this._slider)[this.options.Vertical ? "top" : "left"]); this._c = this._target - this._b; this.onStart(); this.Move(); }, //移动 Move: function() { clearTimeout(this._timer); //未到达目标继续移动否则进行下一次滑动 if (this._c && this._t < this.Duration) { this.MoveTo(Math.round(this.Tween(this._t++, this._b, this._c, this.Duration))); this._timer = setTimeout(Bind(this, this.Move), this.Time); }else{ this.MoveTo(this._target); this.Auto && (this._timer = setTimeout(Bind(this, this.Next), this.Pause)); } }, //移动到 MoveTo: function(i) { this._slider.style[this._css] = i + "px"; }, //下一个 Next: function() { this.Run(++this.Index); }, //上一个 Previous: function() { this.Run(--this.Index); }, //停止 Stop: function() { clearTimeout(this._timer); this.MoveTo(this._target); } }; </script> </head> <body> <style type="text/css"> .container, .container img{280px; height:200px;} .container{border:1px solid #333;} .container img{border:0;} </style> <div class="container" id="idContainer"> <table id="idSlider" border="0" cellpadding="0" cellspacing="0"> <tr> <td><a href="http://www.cnblogs.com/cloudgamer/archive/2009/01/06/Tween.html"><img src="/articleimg/2009/09/7031/r_rt_1.jpg"/></a></td> </tr> <tr> <td><a href="http://www.cnblogs.com/cloudgamer/archive/2008/07/21/ImgCropper.html"><img src="/articleimg/2009/09/7031/r_rt_5.jpg"/></a></td> </tr> <tr> <td><a href="http://www.cnblogs.com/cloudgamer/archive/2008/11/17/Drag.html"><img src="/articleimg/2009/09/7031/r_rt_3.jpg"/></a></td> </tr> </table> </div> <br /> <br /> <style type="text/css"> .num{ position:absolute; right:5px; bottom:5px;} .num li{ float: left; list-style:none; color: #fff; text-align: center; line-height: 16px; 16px; height: 16px; font-family: Arial; font-size: 12px; cursor: pointer; margin: 1px; border: 1px solid #707070; background-color: #060a0b; } .num li.on{ line-height: 18px; 18px; height: 18px; font-size: 14px; border: 0; background-color: #ce0609; font-weight: bold; } </style> <div class="container" id="idContainer2"> <table id="idSlider2" border="0" cellpadding="0" cellspacing="0"> <tr> <td><a href="http://www.cnblogs.com/cloudgamer/archive/2009/03/11/color.html"><img src="/articleimg/2009/09/7031/r_4.jpg"/></a></td> <td><a href="http://www.cnblogs.com/cloudgamer/archive/2008/12/24/Slider.html"><img src="/articleimg/2009/09/7031/r_3.jpg"/></a></td> <td><a href="http://www.cnblogs.com/cloudgamer/archive/2008/12/03/Resize.html"><img src="/articleimg/2009/09/7031/r_rt_2.jpg"/></a></td> </tr> </table> <ul class="num" id="idNum"> </ul> </div> <br /> <div> <input id="idAuto" type="button" value="停止" /> <input id="idPre" type="button" value="<<" /> <input id="idNext" type="button" value=">>" /> <select id="idTween"> <option value="0">默认缓动</option> <option value="1">方式1</option> <option value="2">方式2</option> </select> </div> <script> new SlideTrans("idContainer", "idSlider", 3).Run(); /////////////////////////////////////////////////////////// var forEach = function(array, callback, thisObject){ if(array.forEach){ array.forEach(callback, thisObject); }else{ for (var i = 0, len = array.length; i < len; i++) { callback.call(thisObject, array[i], i, array); } } } var st = new SlideTrans("idContainer2", "idSlider2", 3, { Vertical: false }); var nums = []; //插入数字 for(var i = 0, n = st._count - 1; i <= n;){ (nums[i] = $("idNum").appendChild(document.createElement("li"))).innerHTML = ++i; } forEach(nums, function(o, i){ o.onmouseover = function(){ o.className = "on"; st.Auto = false; st.Run(i); } o.onmouseout = function(){ o.className = ""; st.Auto = true; st.Run(); } }) //设置按钮样式 st.onStart = function(){ forEach(nums, function(o, i){ o.className = st.Index == i ? "on" : ""; }) } $("idAuto").onclick = function(){ if(st.Auto){ st.Auto = false; st.Stop(); this.value = "自动"; }else{ st.Auto = true; st.Run(); this.value = "停止"; } } $("idNext").onclick = function(){ st.Next(); } $("idPre").onclick = function(){ st.Previous(); } $("idTween").onchange = function(){ switch (parseInt(this.value)){ case 2 : st.Tween = Tween.Bounce.easeOut; break; case 1 : st.Tween = Tween.Back.easeOut; break; default : st.Tween = Tween.Quart.easeOut; } } st.Run(); </script> </body> </html>

[Ctrl+A 全部选择提示：你可先修改部分代码，再按运行]

程序说明

原理就是通过不断设置滑动对象的left(水平切换)和top(垂直切换)来实现图片切换的动态效果。

首先需要一个容器，程序会自动设置容器overflow为hidden，如果不是相对或绝对定位会同时设置position为relative，
滑动对象会设置为绝对定位：

var p = CurrentStyle(this._container).position;
p == "relative" || p == "absolute" || (this._container.style.position = "relative");
this._container.style.overflow = "hidden";
this._slider.style.position = "absolute";

如果没有设置Change切换参数属性，会自动根据滑动对象获取：

this.Change = this.options.Change ? this.options.Change :
this._slider[bVertical ? "offsetHeight" : "offsetWidth"] / this._count;

执行Run方法就会开始进入切换，其中有一个可选参数用来重新设置要切换的图片索引：

index == undefined && (index = this.Index);
index < 0 && (index = this._count - 1) || index >= this._count && (index = 0);
== undefined && (index = this.Index);
index < 0 && (index = this._count - 1) || index >= this._count && (index = 0);

之后就到设置使用 tween缓动时需要的参数了，
包括_target(目标值)、_t(时间)、_b(初始值)和_c(变化量)：

this._target = -Math.abs(this.Change) * (this.Index = index);
this._t = 0;
this._b = parseInt(CurrentStyle(this._slider)[this.options.Vertical ? "top" : "left"]);
this._c = this._target - this._b;

还有Duration(持续时间)是自定义属性。

参数设置好后就执行Move程序开始移动了。
里面很简单，首先判断_c是否有值（等于0表示不需要移动）和_t是否到达Duration，
未满足条件就继续移动，否则直接移动到目标值并进行下一次切换：

if (this._c && this._t < this.Duration) {
    this.MoveTo(Math.round(this.Tween(this._t++, this._b, this._c, this.Duration)));
    this._timer = setTimeout(Bind(this, this.Move), this.Time);
}else{
    this.MoveTo(this._target);
    this.Auto && (this._timer = setTimeout(Bind(this, this.Next), this.Pause));

使用说明

实例化需要3个参数，分别是容器对象，滑动对象和切换数量，之后可以直接执行Run方法运行：

new SlideTrans("idContainer", "idSlider", 3).Run();

还有以下可选属性：

Vertical: true,//是否垂直方向（方向不能改）
Auto: true,//是否自动
Change: 0,//改变量
Duration: 50,//滑动持续时间
Time: 10,//滑动延时
Pause: 2000,//停顿时间(Auto为true时有效)
onStart: function(){},//开始转换时执行
onFinish: function(){},//完成转换时执行
Tween: Tween.Quart.easeOut//tween算子

其中Vertical初始化后就不能修改，Tween算子可参照这里的缓动效果选择（实例中选了其中3个）。

还有提供了以下方法：

Next: 切换下一个
Previous: 切换上一个
Stop: 停止自动切换
还有上面说到的Run

程序代码：

代码拷贝框
var SlideTrans = function(container, slider, count, options) { this._slider = $(slider); this._container = $(container);//容器对象 this._timer = null;//定时器 this._count = Math.abs(count);//切换数量 this._target = 0;//目标值 this._t = this._b = this._c = 0;//tween参数 this.Index = 0;//当前索引 this.SetOptions(options); this.Auto = !!this.options.Auto; this.Duration = Math.abs(this.options.Duration); this.Time = Math.abs(this.options.Time); this.Pause = Math.abs(this.options.Pause); this.Tween = this.options.Tween; this.onStart = this.options.onStart; this.onFinish = this.options.onFinish; var bVertical = !!this.options.Vertical; this._css = bVertical ? "top" : "left";//方向 //样式设置 var p = CurrentStyle(this._container).position; p == "relative" || p == "absolute" || (this._container.style.position = "relative"); this._container.style.overflow = "hidden"; this._slider.style.position = "absolute"; this.Change = this.options.Change ? this.options.Change : this._slider[bVertical ? "offsetHeight" : "offsetWidth"] / this._count; }; SlideTrans.prototype = { //设置默认属性 SetOptions: function(options) { this.options = {//默认值 Vertical: true,//是否垂直方向（方向不能改） Auto: true,//是否自动 Change: 0,//改变量 Duration: 50,//滑动持续时间 Time: 10,//滑动延时 Pause: 2000,//停顿时间(Auto为true时有效) onStart: function(){},//开始转换时执行 onFinish: function(){},//完成转换时执行 Tween: Tween.Quart.easeOut//tween算子 }; Extend(this.options, options || {}); }, //开始切换 Run: function(index) { //修正index index == undefined && (index = this.Index); index < 0 && (index = this._count - 1) || index >= this._count && (index = 0); //设置参数 this._target = -Math.abs(this.Change) * (this.Index = index); this._t = 0; this._b = parseInt(CurrentStyle(this._slider)[this.options.Vertical ? "top" : "left"]); this._c = this._target - this._b; this.onStart(); this.Move(); }, //移动 Move: function() { clearTimeout(this._timer); //未到达目标继续移动否则进行下一次滑动 if (this._c && this._t < this.Duration) { this.MoveTo(Math.round(this.Tween(this._t++, this._b, this._c, this.Duration))); this._timer = setTimeout(Bind(this, this.Move), this.Time); }else{ this.MoveTo(this._target); this.Auto && (this._timer = setTimeout(Bind(this, this.Next), this.Pause)); } }, //移动到 MoveTo: function(i) { this._slider.style[this._css] = i + "px"; }, //下一个 Next: function() { this.Run(++this.Index); }, //上一个 Previous: function() { this.Run(--this.Index); }, //停止 Stop: function() { clearTimeout(this._timer); this.MoveTo(this._target); } };
[Ctrl+A 全部选择然后拷贝]

下载测试代码

本文链接：http://www.blueidea.com/tech/web/2009/7031.asp　

相关阅读:
简单的模板解析函数
HTML通过事件传递参数到js 二 event
HTML通过事件传递参数到js一
通过this获取当前点击选项相关数据
LeetCode 20. 有效的括号(Valid Parentheses)
LeetCode 459. 重复的子字符串(Repeated Substring Pattern)
LeetCode 14. 最长公共前缀(Longest Common Prefix)
LeetCode 168. Excel表列名称(Excel Sheet Column Title)
LeetCode 171. Excel表列序号(Excel Sheet Column Number) 22
LeetCode 665. 非递减数列(Non-decreasing Array)

原文地址：https://www.cnblogs.com/zhangxiaopeng/p/5138662.html